“A crew of 12 people rode out the hurricane in a hurricane-proof bunker on Johnston Atoll;
the crew estimated winds reached over 100 mph (160 km/h), which damaged trees on the island
but did not impact the island’s bird population.”

I wonder how the birds survived 100 mph winds.

Hurrican-proof bunker cannot be that deep because the highest elevation of Johnston Atoll is
5 meters = about = 15 feet. None the less people figured out a way to survive too.

“…Ioke produced a storm surge and high surf in excess of 30 ft (9.1 m) along the southwestern
coastline of Alaska …”

Big waves.

“Ioke maintained at least Category 4 status, or wind speeds greater than 131 mph (211 km/h),
for 198 consecutive hours, which was the longest continuous time period at that intensity ever
observed for any tropical cyclone anywhere on Earth.”

Less wind speed storms last longer?

“…traversed the Pacific for 17 days…”

Difficult to imagine the distance it traveled. I guess it did not stay in one place for 17 days.

“There were no meteorological observations on the island, but the crew estimated tropical storm force
winds lasted for about 27 hours with hurricane force winds lasting six to eight hours; peak wind gusts
were estimated at 110 to 130 mph (180 to 210 km/h). The crew sustained no injuries, and their ship
received only minor damage. Hurricane Ioke, with a portion of its eye crossing the atoll, left an
estimated 15% of the palm trees on the island with their tops blown off, with some ironwood trees
blown over; the island bird population was unaffected.”

There are probably large amount of experimental data about the shape of a boat and
the action of waves on the hull of the boat. Some of that data might even be available.

I saw youtube videos about oil-tanker boats.
Some of those boats are big. Most of the oil tanker boats body is in the water when the
boat is loaded. In the video it was stated that the tanker needs a small engines. And
the tanker operation cost is so low that it adds only 2 cents per gallon to the gasoline price.
(That is when the taxpayers clean up Exon-Valdez in Alaska, but let’s not piss them off.)

So some people figured out a way to move large boats with high efficiency.

The effect of waves on a seasteading platform may be scary in a big storm. Different shape
platforms might respond differently to a storm and to big waves.

What would be the guide lines?

I would think: it should float, It should float even when it is full of water,
it should be self righting, cheap to build, easy to maintain, and should have a multi purpose,
… etc…

I would think: Ferro-cement would be the cheapest. To make it float it would be nice to
incorporate some kind of synthetic foam. A V-shape hull may be the best.

Components of ferro-cement are probably the cheapest and most available on land.
Synthetic foam could be polyurethane. Polyurethane foam is widely used for heat insulation,
and for retrofit heat insulation. The price might be high, but it is available.

The price of the final product depends on labor cost too. When DIY or unskilled labor can
be utilized, the final price can be lower. Most ferro-cement boat construction documents
state that the construction can be done with relatively low skills.

The shape of the platform:
I consider the rolling effect of waves on a boat. A boat can be positioned with bow against
the waves, and with side against the waves. The less surface a wave gets, the less effect it
makes and the safer it is. I saw some square shape platform designs. A square shape platform
cannot minimize wave effect by turning with bow against the waves.

There might be lots of data to support the rectangular designs, I just do not know how to
get access to that data. None the less, the data must exist because of the large boats and
boat building engineers, and businesses. An engineering firm would probably have to show
experimental data to the customer about the specifications of a boat to be biult.
That data is not available, but the final shape of the product (boat) is available.

So the final shape is mostly rectangular and V-shaped. The bow again <-shaped, and the
aft is ]-shaped. Kind of like <===] and V. (I am not trying to be obscene.)

In my opinion, simplicity is a big factor of the success to build a platform.

Building a platform is not enough. It has to be launched. It has to be transported (towed or
powered) to anchoring location. And it has to be anchored.
To build one, there necessary to find an available space where it could be launched to water.
There is no point to build one in the middle of the desert, and to leave it there.

Some calculation would be necessary to estimate the cost of construction to ensure success.
Success is a floating platform anchored outside EEZ, and no one would sink it, and some people
would utilize it at least for some time.